Optical body having a concave-convex structure, method for manufacturing the optical body, and light emitting device

An optical body comprising:

• a base material;
• a first concave-convex structure that is formed on at least one surface of the base material and that extracts internally propagating light that is injected into an inside of the base material from a side surface of the base material, and
• a second concave-convex structure that is formed on the at least one surface of the base material where the first concave-convex structure is formed in a region where the first concave-convex structure is not formed and wherein an average period of concavity and convexity of the second concave-convex structure is less than the minimum value of the visible light wavelength band,
• wherein an average period of concavity and convexity of the first concave-convex structure is more than or equal to a minimum value of a visible light wavelength band and less than or equal to 10 μm, and
• wherein the first concave-convex structure has a height of from 100 to 500 nm and the second concave-convex structure has a height of more than or equal to 150 nm.